Bors links to the wrong build in GitHub Actions

[pietroalbini]

When bors reports that a build failed in GitHub Actions, it links to the "bors build finished" meta-job instead of the actual job tha failed. This makes the UX for our contributors worse.

[pietroalbini]

There isn't a trivial way to implement this without changing bors, and the issue might be "solved" by enabling RLA for GHA. This is not a blocker for migrating to GHA, but it would be nice to get it fixed anyway.